Abstract

A focused image of the sun was noted under circumstances which suggested that the image was due to a tiny mirror operating in a manner analogous to a pinhole lens. It seemed appropriate to call this hypothetical device a pinhead mirror. Some tiny, flat mirrors were made and tested. They produced dim, inverted images of varying quality at various object and image distances. The 0.3-mm mirror produced the sharpest image. When this mirror was 45 mm from the object its image appeared in focus at 100 to beyond 1300-mm distances. These operating characteristics are similar to those predicted for a pinhole lens. This suggests that pinhead mirrors and pinhole lenses obey similar principles of geometric optics. Perhaps the pinhead mirror's special ability to change the direction of light while simultaneously restoring its original topology to various magnifications with great depth of field will prove useful in optical computing or integrated optical devices.

© 1986 Optical Society of America